The specific objective of this cooperative research project is to evaluate the clinical effectiveness of chemotherapeutic agents in the treatment of patients with advanced prostatic cancer who have failed to respond or are no longer responding to existing hormonal therapy. As described in detail in the protocols attached, patients will be randomized into treatment groups for each protocol. By using similar patients from several institutions, the project will be able to evaluate potential agents in the treatment of prostatic carcinoma more rapidly than any single institution alone. Several drugs are currently under study. PROTOCOL 100: 5 Fluorouacil and Cyclophosphamide are being compared to standard treatment (hormones, analgesics, radiotherapy and surgery). PROTOCOL 200: Estracyt and Streptozotocin are being evaluated against standard treatment. PROTOCOL 300: Procarbazine and DTIC are being compared with cyclophosphamide which PROTOCOL 100 data indicated had potential activity against this neoplasm. Treatment with the chemotherapeutic agent will last 12 weeks. If the patient shows progression of his disease at 12 weeks, he will be switched to another agent, after being allowed to recover from any previous toxicity. All patients in all treatment groups will be followed until death. A total of 44 patients have been entered into the above protocols from this institution as of June 1, 1975. Basic decisions to evaluate other chemotherapeutic agents will be made by the members of the National Prostatic Cancer Project in counsel with the National Cancer Institute.